Solvent-free synthesis of CoTe2 alloy efficient for selective production of singlet oxygen to remove sulfadiazine

Various candidates have been designed for the selective production of singlet oxygen (¹O₂) to quickly remove sulfadiazine (SDZ) that poses significant risks to both human health and the environment. However, minimal attention has been focused on metal tellurides. Herein, a two-dimensional CoTe₂ alloy catalyst was prepared via a solvent-free method to selectively produce ¹O₂ for the complete SDZ degradation in 12 min. The CoTe₂/PMS system exhibited efficient SDZ degradation, with a kinetic rate constant of 0.404 min⁻¹, surpassing the performance of most previously reported catalysts. Experimental results reveal that the coordination of Co with Te adjusted the electronic structure of the catalyst, Co with weaker oxidation state was responsible for the generation of ¹O₂ from the oxidation of PMS via direct electron transfer. The formation of the CoTe₂ alloy significantly reduces the dissolution of Co, allowing CoTe₂/PMS to maintain high efficiency in cycling experiments and aqueous ionic interference experiments. The ecological toxicity of SDZ was notably reduced. Overall, this study highlights the potential of Te-based alloy for the selective production of ¹O₂, offering a promising approach for antibiotic removal in wastewater treatment.